http://www.businessinsider.com/the-most-impor...10-2015-12

http://www.wsj.com/articles/facebook-bends-to...1449676734

“People want to give their friends the same experience they had,” he said. “If you had a good experience you’re more likely to want your friends to experience the same thing. If something loads slowly and there are ads obscuring the content, perhaps they don’t want to subject their friends to that.”